There are many different types of fasteners, some particularly adapted to a specific fastening function, others of more general application. Thus, buttons, which cooperate with buttonholes, are particularly adapted for textile use, since the buttonhole must be flexible, as are pop studs, in which one member with a head is inserted into a member with a recess over a spring which retains the head in the recess until force is applied to pull the two members apart.
Screws, which engage in threaded apertures or which are self tapping, are another form of fastener used for securing more rigid objects together or for fixing objects to walls, often into plugs of fibre or plastic inserted into drilled holes, causing the plugs to expand into close contact with the hole wall to be retained there by friction. Screws are removed by the application of torsion of opposite hand to that which inserted them. Spring clips are pushed in, resiliently narrowing to pass a detent, and expanding to retain them. They are removed by pulling them out against the resilience of the spring. Rivets are like spring clips except that they are permanently deformed once past a detent, and cannot generally be removed without destruction.